Internally divisible process chamber using a shutter disk assembly

ABSTRACT

Apparatus and methods for forming and using internally divisible physical vapor deposition (PVD) process chambers using shutter disks are provided herein. In some embodiments, an internally divisible process chamber may include an upper chamber portion having a conical shield, a conical adaptor, a cover ring, and a target, a lower chamber portion having a substrate support having inner and outer deposition rings, and wherein the substrate support is vertically movable, and a shutter disk assembly configured to internally divide the process chamber and create a separate sealed deposition cavity and a separate sealed oxidation cavity, wherein the shutter disk assembly includes one or more seals disposed along its outer edges and configured to contact at least one of the conical shield, the conical adaptor, or the deposition rings to form the separate sealed deposition and oxidation cavities.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of United States patent applicationSer. No. 17/183,587, filed Feb. 24, 2021, which claims benefit of UnitedStates provisional patent application Ser. No. 63/109,939, filed Nov. 5,2020 which is herein incorporated by reference in its entirety.

FIELD

Embodiments of the present disclosure generally relate to internallydivisible Physical vapor deposition (PVD) process chambers using shutterdisks.

BACKGROUND

There is a need to repeatably deposit high uniformity films, forexample, Magnesium Oxide (MgO) films among others, in a single processchamber. Depositing Mg and then oxidizing it in a single PVD chamber,for example, has poor substrate-to-substrate repeatability because mostof the oxygen for oxidizing the substrate is used up oxidizing thetargets and shields in the chamber. The amount of oxygen used on thetarget and shields depends on chamber conditions, therefore the amountof oxygen available for each substrate can vary greatly.

Typically, in order to produce very repeatable layers of oxidized Mg, Mgis deposited in one chamber and the substrate is then moved to anotherchamber to oxidize the Mg film. This sequence may require multiplelayers, for example, as many as 12 layers of MgO, and has extremely lowthroughput.

Thus, the inventors have provided embodiments of internally divisibleprocess chambers to allow film deposition and oxidation/gas reactions onsubstrates to occur within a single process chamber without reactingwith other deposited surfaces in chamber.

SUMMARY

Apparatus and methods for forming and using internally divisiblephysical vapor deposition (PVD) process chambers using shutter disks areprovided herein. In some embodiments, an internally divisible processchamber may include an upper chamber portion having a conical shield, aconical adaptor, a cover ring, and a target, a lower chamber portionhaving a substrate support having inner and outer deposition rings, andwherein the substrate support is vertically movable, and a shutter diskassembly configured to internally divide the process chamber and createa separate sealed deposition cavity and a separate sealed oxidationcavity, wherein the shutter disk assembly includes one or more sealsdisposed along its outer edges and configured to contact at least one ofthe conical shield, the conical adaptor, or the deposition rings to formthe separate sealed deposition and oxidation cavities.

In some embodiments, a method for forming metal oxide layers on asubstrate in a single internally divisible process chamber having anupper chamber and a lower chamber may include moving the substrate intoa deposition position within a deposition cavity formed in the singleinternally divisible process chamber, depositing a metal film from atarget onto the substrate, lowering the substrate into the lowerchamber, creating a seal using a shutter disk assembly to divide theprocess chamber into an upper deposition cavity and a lower oxidationcavity, wherein the substrate is within the lower oxidation cavity,oxidizing the metal film deposited on the substrate by introducingoxygen into the oxidation cavity, purging the oxidation cavity to removeresidual oxygen, and opening the chamber dividing seal.

Other and further embodiments of the present disclosure are describedbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure, briefly summarized above anddiscussed in greater detail below, can be understood by reference to theillustrative embodiments of the disclosure depicted in the appendeddrawings. However, the appended drawings illustrate only typicalembodiments of the disclosure and are therefore not to be consideredlimiting of scope, for the disclosure may admit to other equallyeffective embodiments.

FIG. 1 depicts a cross-sectional view of an internally divisibleprocessing chamber in accordance with some embodiments of the presentdisclosure.

FIG. 2 depicts another embodiment of an internally divisible processingchamber using a shutter disk assembly in accordance with someembodiments of the present disclosure.

FIG. 3 depicts another embodiment of an internally divisible processingchamber using a shutter disk assembly in accordance with someembodiments of the present disclosure.

FIG. 4 depicts another embodiment of an internally divisible processingchamber using a shutter disk assembly in accordance with someembodiments of the present disclosure.

FIGS. 5A and 5B depict cross-section views of a lip structure for ashutter disk assembly in accordance with some embodiments of the presentdisclosure.

FIGS. 6A-6C depict a gas distribution shutter disk assembly inaccordance with some embodiments of the present disclosure.

FIGS. 7A and 7B depict additional embodiments of an internally divisibleprocessing chamber using a shutter disk assembly in accordance with someembodiments of the present disclosure.

FIG. 8 is a flowchart of a of a process performed by the internallydivisible substrate processing chambers in accordance with someembodiments of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. The figures are not drawn to scale and may be simplifiedfor clarity. Elements and features of one embodiment may be beneficiallyincorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

Embodiments of internally divisible substrate processing chambers toallow gas reactions on substrates without reacting other depositedsurfaces in the chambers are provided herein. The inventive processingchambers and associated components allow in-situ gas reaction withon-substrate films while preventing other deposited surfaces in thechamber from reacting with the same gas(es). The inventive chamberdesigns can advantageously segregate and seal the substrate in a smallerinternal cavity for gas reactions. That internal cavity is the pumpedand purged to remove all reactive gas before unsealing. The substratecan receive multiple layers of deposition and reaction, all within thesingle process chamber.

The inventive chamber designs can be internally divisible in differentways using various different chamber components and shutter diskassembly embodiments as described below in more detail.

FIG. 1 depicts a schematic cross-sectional view of a processing chamber(process chamber 100) in accordance with some embodiments of the presentdisclosure. In some embodiments, the chamber 100 may be a clovermulti-cathode PVD chamber. The process chamber 100 includes an upperchamber 102 and a lower chamber 104. The lower chamber 102 includes asubstrate support 110 disposed within the process chamber 100 that isconfigured to support a substrate 108. In some embodiments, thesubstrate support 110 may be a rotating pedestal. In some embodiments,the substrate support 110 may be vertically movable.

The upper chamber includes a power supply 112 may be coupled to each ofthe plurality of cathodes 102. The power supply 112 may include directcurrent (DC), pulsed DC, or radio frequency (RF) power. The rotatableshield 106 may expose two or more of the plurality of cathodes 102 andshield remaining cathodes 102 from cross-contamination duringsputtering. The cross-contamination results from physical movement ortransfer of a deposition material from one of the cathodes 102 toanother one of the cathodes 102. Each cathode 102 is positioned over acorresponding target 114. To sputter the selected target, the rotatableshield 106 is rotated to expose the selected target to be sputtered. Thetargets 114 may be formed of any material desired to be sputtered ontothe substrate 108. In some embodiments, the upper chamber 102 includes ashroud 126, which is a long tube 128 that does not block a line of sightfrom the target 114 to a substrate disposed on the substrate support110, corresponding to each cathode 102.

The upper chamber 102 further includes a conical adapter 116 and aconical shield 118. A top section of the conical shield 118 isconfigured to surround a lower portion of the rotatable shield 106 and abottom section of the conical shield 118 is configured to surround thesubstrate support 110 when the substrate support is moved verticallyupward into the upper chamber for substrate processing. Before thesubstrate 108 moves into or out of the chamber, the substrate 108 canmove below a conical shield 118 disposed on a lower portion of theprocess chamber. A cover ring 120 is disposed on top of the conicalshield 118 and surrounds the substrate 108. When the substrate support110 moves down, the substrate 108 can be lifted up with a robotic arm(not shown) before the substrate 108 moves out of the chamber.

The cover ring 120 can include a ring portion 122 that curves up and hasa predefined thickness to form a dish or bowl in which the substrate canbe disposed with the ring portion 122 surrounding and disposed above thesubstrate 108. The cover ring 120 can also include a predefined gap 124and a predefined length with respect to the conical shield 118. Thus,when materials are deposited on the substrate 108, the materials areprevented or substantially prevented from depositing below the substratesupport 110 or outside of the conical shield 118. Controlling thedeposition of materials as described advantageously prevents or reducesthe spread of contaminants to the substrate 108 or within the processchamber. The inner and outer deposition rings 140, 142 further preventdeposition of the material below the substrate support 110.

When the chamber 100 is not performing depositions processes to depositmaterial on the substrate 108, the substrate support is lowered into thelower chamber 104 to perform oxidations processes to oxidize thematerial deposited on the substrate from the target 114, for example Mg.In order to produce very repeatable layers of oxidized Mg or other gasreactions without reacting other deposited surfaces in the chamber, ashutter disk assembly 150 is used to internally divides variousvolumes/cavities to perform the desired processing. In some embodiments,the shutter disk assembly 150 may be a single piece flat plate or it maybe a multi-layer showerhead have internal conduits and gas distributionchannels to evenly distribute gases provide to it.

The shutter disk assembly 150 may be moved into place via a robottransfer assembly 152 which can rotate to move the shutter disk assembly150 into the chamber through a shutter disk opening 156 in the chamber.The robot transfer assembly 152 may include an arm 154 that supports theshutter disk assembly 150. In some embodiments, the shutter diskassembly 150 may be removably coupled to the arm 154 or may just bysupport by the arm 154.

In at least one embodiment, a seal can be created between the shutterdisk assembly 150 and chamber features such as a bottom portion of aconical adapter 116 of the upper housing, or the conical shield 118disposed in the upper housing. The shutter disk may include one moreseals 160, 162 (e.g., an O-ring, or other type of seal) placed at itsouter edges that contacts other chamber components to form a seal andcreate separated cavities. For example, the shutter disk assembly 150may include an upper seal 162 that forms a seal between the shutter diskassembly 150 and the conical adaptor 116 or conical shield 118. Inaddition, the shutter disk assembly 150 may include a lower seal 160that forms a seal between the shutter disk assembly 150 and the outerdeposition ring 142. The substrate remains on the substrate support, forexample on an electro-static chuck, below the shutter disk. The pedestalthen moves up, creating a seal between the shutter disk outer edge andthe lower lip of the conical adapter or shield of the upper housing ofthe process chamber. This divides the chamber 100 and forms a depositioncavity 130, an oxidation cavity 132, and a third cavity 134.

When the shutter disk assembly 150 is moved into place to divide thechamber and perform an oxidation process, for example, Oxygen (O₂) canbe introduced into the oxidation cavity 132 through a first gas conduit158. In some embodiments, the first gas conduit 158 may be disposedwithin the shaft of the robot transfer assembly 152 as shown in FIG. 1.The O₂ would then flow through the arm 154 which would be coupled to aninlet in the shutter disk assembly 150. In some embodiments, the shutterdisk assembly may act as a showerhead as shown and described withrespect to FIG. 3. In other embodiments, the processing gas (e.g., O₂)can be introduced through a conduit directly coupled to the shutter diskassembly 150 when it is moved into place for oxidation processing.

When it is time to clear the process chamber 100 of the processing gas(e.g., O₂), an inert gas such as Argon may be introduced into thechamber via inlet 170 and gases by be exhausted through outlet 172 usinga pump (not shown). In some embodiments, the same conduit (e.g., thefirs gas conduit 158) used to introduce the processing gas may be usedto introduce the inert cleaning gas (e.g., Ar) to clear out theprocessing gas.

FIG. 2 depicts another embodiment of how the chamber can be internallydivided using a shutter disk assembly 150. In embodiments consistentwith FIG. 2, instead of the substrate support pedestal 110 moving up toform the shutter disk seal and divide the chamber, the shutter diskassembly 150 is moved into place by using one or more chamber-mountedactuators 202 to lift the shutter disk assembly 150 and form a sealbetween the shutter disk assembly 150 and the conical adapter 116 orshield 118. In some embodiments, there may be a three chamber-mountedactuators 202 to ensure the disk is held level and form a proper seal.Each chamber mounted actuator 202 includes bellows 204 and a support arm206. As shown in FIG. 2, the shutter disk assembly 150 may be a flatplate having seals 210 (e.g., O-rings or the like) disposed on a topsurface to from the seal with the conical adapter 116 or shield 118. Inthe embodiments, shown in FIG. 2, two cavities are formed when theshutter disk assembly 150 is moved into place for oxidation processingof the substrate; the deposition cavity 130 which is protected fromlower chamber oxidation process performed in oxidation cavity 132.

In embodiments consistent with FIG. 2, once this seal is created, aprocessing gas such as Oxygen (O₂) can be introduced into the lowerportion of the chamber through the standard gas inlet 170 to oxidize thedeposited film on substrate, and later pumped out through outlet 172using a standard chamber pump. The processing gas may be cleared out ofthe chamber as discussed above with respect to FIG. 1.

FIG. 3 depicts another embodiment of how the chamber can be internallydivided using a shutter disk assembly. In embodiments consistent withFIG. 3, the robot transfer assembly 152, which can rotate to move theshutter disk assembly 150 into the chamber through a shutter diskopening 156 in the chamber, is also able to move vertically in a Zdirection 310. A seal between shutter disk assembly 150 and the conicaladapter 116 or shield 118 is formed as described above via O-ring seals302. Once shutter disk assembly 150 is in the upper position, O₂ orother processing gases can be flowed into and pumped of the oxidationcavity 132 without getting any into deposition area 130.

In embodiments consistent with FIG. 3, the shutter disk assembly 150 islarger than pedestal 110 so that substrate 108 on pedestal 110 couldstill pass through the bottom opening in conical shield 118. In someembodiments, the shutter disk assembly 150 and arm 154 could beone-piece divider plate.

FIG. 4 depicts another embodiment of how the chamber can be internallydivided using a shutter disk assembly. Similar to embodiments describedwith respect to FIG. 3, the robot transfer assembly 152 able to movevertically in a Z direction 310. However, in embodiments consistent withFIG. 4, the shutter disk assembly 150 is lowered onto one or moresupport posts 402 to form oxidation cavity 132 which is separated fromdeposition cavity 130. A seal is formed using O-rings as describedabove, or using a simple lip seal 410. In some embodiments, a processinggas such as Oxygen (O₂) can be introduced into the lower portion of thechamber through the standard gas inlet 412 located at the bottom of thechamber within the oxidation cavity 132 to oxidize the deposited film onsubstrate, and later pumped out through outlet 414, also within at thebottom of the chamber within the oxidation cavity 132, using a standardchamber pump.

In any of the embodiments discussed with respect to FIGS. 1-4, insteadof a tight seal using O-rings (e.g., seals 160, 162, 210, 302), someother type of simple lip seal (e.g., 410), or a seal formed by minimaldirect contact between the shutter disk and the conical adapter 116 orshield 118, may be used if a low gas pressure difference is maintainedwhen performing oxidation processes or other gas processes. In someembodiments, an annular lip seal 502 having a cross-section as shown inFIGS. 5A and 5B is disposed within a top groove 504 formed on a topand/or bottom surface of the shutter disk assembly 150.

As discussed with respect to FIG. 1, the shutter disk assembly 150 mayitself by a showerhead, and Oxygen to a distribution disk shower headcan be supplied through the actuator mechanism. This is shown in moredetail in FIGS. 6A-6C. In some embodiments, the gas distribution shutterdisk assembly 150 may include a top plate 602 and a bottom plate 604with a gas distribution disk 606 disposed between them. The bottom plate604 may include a central opening and a lip 612 on which the gasdistribution disk 606 sits on and is retained within. The gasdistribution disk 606 may include a plurality of gas distribution holes608 coupled to one or more channels 610. At least one of the channels610 formed in the gas distribution disk 606 couples to a channel formedin either the top plate 602 or the bottom plate 604 which is thencoupled to a gas source. For example, the gas source may be a gassupplying conduit formed in the shutter disk robot transfer arm 154 orsome other gas supplying conduit.

FIGS. 7A and 7B depicts other embodiments of how the chamber can beinternally divided using a shutter disk assembly. In some embodimentsconsistent with FIG. 7A, a seal between a shutter disk assembly 150 andthe rotating pedestal outer support cover ring 142, which can include aring portion that curves up and has a predefined thickness to form adish or bowl in which the substrate can be disposed with the ringportion surrounding and disposed above the substrate (also referred toas a dish or bowl). O-ring seals 710 may be used to create the seal. Inthese embodiments, a shutter disk is attached to the underside of theshutter arm. The shutter disk is rotated into position and the shutterdisk forms a seal with the dish creating a small volume within thepedestal cavity containing both the ESC and substrate. O2 is introducedinto this small volume through the shutter arm or other gas-supplyfeatures in the chamber. The O2 is later pumped out through thepedestal, using features such as the unused backside gas feedthrough tothe ESC.

In some embodiments consistent with FIG. 7B, after the shutter diskassembly 150 is placed on the rotating pedestal outer support cover ring142, the substrate support 110 moves up to form a seal between theshutter disk assembly 150 and the conical shield 118, or conical adaptor116. In embodiments consistent with both FIGS. 7A and 7B, processing andpurge gases may be flowed through conduits 702 formed in the substratesupport 110 which is coupled to one or more inlet conduits on theshutter disk assembly 150.

FIG. 8 is a flowchart of at least one embodiment of a process 800performed by the internally divisible substrate processing chambersdescribed herein. The method begins at 802 where a substrate 108 istransferred into chamber 100 using a robotic arm mechanism. As 804, thesubstrate 108 is moved to deposition position and mg is deposited from atarget onto the substrate 108 using a PVD process in upper chamber 102.At 806, the substrate is lowered into the lower chamber 104 and thechamber dividing seal is created using shutter disk assembly 150,dividing upper deposition cavity 130 from the oxidation cavity 132. At808, oxidation of the mg on the substrate occurs by introducing oxygeninto the oxidation cavity 132. At 810, the oxidation cavity 132 ispumped and purged to remove residual oxygen and the chamber dividingseal is opened up. If additional layers are desired, steps 804-810 arerepeated until desired MgO layer thickness and other properties areachieved. At 812, the substrate is transferred out of chamber and theprocess ends.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof.

1. A method for forming metal oxide layers on a substrate in a single internally divisible process chamber having an upper chamber and a lower chamber, comprising: moving the substrate into a deposition position within a deposition cavity formed in the single internally divisible process chamber; depositing a metal film from a target onto the substrate; lowering the substrate into the lower chamber; creating a seal using a shutter disk assembly to divide the process chamber into a sealed upper deposition cavity and a sealed lower oxidation cavity, wherein the substrate is within the lower oxidation cavity; oxidizing the metal film deposited on the substrate by introducing oxygen into the oxidation cavity; purging the oxidation cavity to remove residual oxygen; and opening the chamber dividing seal.
 2. The method of claim 1, wherein the lower chamber includes a substrate support having inner and outer deposition rings, and wherein the substrate support is vertically movable.
 3. The method of claim 2, wherein the shutter disk assembly is configured to internally divide the process chamber and create a separate sealed deposition cavity and a separate sealed oxidation cavity, wherein the shutter disk assembly includes one or more seals disposed along its outer edges and configured to contact at least one of a conical shield or conical adaptor, or the deposition rings to form the separate sealed deposition and oxidation cavities.
 4. The internally divisible process chamber of claim 3, wherein the shutter disk assembly includes a lower seal that forms a seal between the shutter disk assembly and the outer deposition ring to create the separate sealed deposition and oxidation cavities.
 5. The internally divisible process chamber of claim 4, wherein a third cavity is formed when an upper seal of the shutter disk assembly is in contact with the lower lip of the conical adaptor and the lower seal of the shutter disk assembly is in contact with the outer deposition ring.
 6. The internally divisible process chamber of claim 5, wherein the substrate support is configured to move vertically to enable contact between the lower seal of the shutter disk assembly and the outer deposition ring.
 7. The internally divisible process chamber of claim 1, wherein the shutter disk assembly includes an upper seal that forms a seal between the shutter disk assembly and a lower lip of a conical shield of the process chamber to create the separate sealed deposition and oxidation cavities.
 8. The internally divisible process chamber of claim 7, wherein the shutter disk assembly includes a lower seal that forms a seal between the shutter disk assembly and the outer deposition ring to create separate sealed deposition and oxidation cavities.
 9. The internally divisible process chamber of claim 8, wherein a third cavity is formed when the upper seal of the shutter disk assembly is in contact with the lower lip of the conical shield and the lower seal of the shutter disk assembly is in contact with the outer deposition ring.
 10. The internally divisible process chamber of claim 1, wherein the lower chamber portion includes a robot transfer assembly having a transfer arm and a rotatable shaft configured to move the shutter disk assembly into the internally divisible process chamber through a shutter disk opening in the chamber.
 11. The internally divisible process chamber of claim 10, wherein a first gas conduit is disposed within the rotatable shaft of the robot transfer assembly, and a second gas conduit disposed in the transfer arm that is fluidly coupled to the first gas conduit and to a shutter disk assembly showerhead configured to introduce oxidation gases into the oxidation cavity.
 12. The internally divisible process chamber of claim 10, wherein the robot transfer assembly is configured to move vertically to enable contact between an upper seal of the shutter disk assembly and a conical adapter or conical shield.
 13. The internally divisible process chamber of claim 1, wherein the shutter disk assembly includes a showerhead, and wherein a first gas conduit is fluidly coupled directly to the showerhead of the shutter disk assembly and configured to introduce Oxygen (O₂) into the oxidation cavity.
 14. The internally divisible process chamber of claim 1, wherein the lower chamber portion includes one or more chamber-mounted actuators configured to lift the shutter disk assembly and form a seal between the shutter disk assembly and a conical adapter or conical shield.
 15. The internally divisible process chamber of claim 14, wherein the lower chamber portion includes three chamber-mounted actuators configured to ensure the shutter disk assembly is held level and forms a proper seal with the conical adapter or conical shield.
 16. The internally divisible process chamber of claim 1, wherein the shutter disk assembly is a flat plate having one or more seal disposed on a top surface to from the seal with a conical adapter or conical shield.
 17. The internally divisible process chamber of claim 1, wherein the shutter disk assembly is a gas distribution showerhead assembly comprising a top plate and a bottom plate with a gas distribution disk disposed between them.
 18. The internally divisible process chamber of claim 17, wherein the bottom plate includes a central opening and a lip on which the gas distribution disk is disposed on and is retained within.
 19. The internally divisible process chamber of claim 17, wherein the gas distribution disk includes a plurality of gas distribution holes coupled to one or more channels, wherein at least one of the channels formed in the gas distribution disk is coupled to a second channel formed in either the top plate or the bottom plate which is further coupled to a gas source. 